Looks like the torque converter is visible through that hole if that is the transmission.
Hank & Natalie Bensley
2001 Double Slide #586.
2021 Cherokee Trailhawk Toad
We've been RV owners since 2002.
Port Orange, FL. Soon we will travel full time for "a while"
Looks like a hole to access the bolts for flex plate to torque converter.
If it was mine, I'd look for a pipe plug to fill the hole - just to prevent the odd chance for road debris to enter (which is highly unlikely given the hole faces the rear of the coach)